Hollow structures have attracted great attention based on the advantage to accommodate volume expansion. However, template removal usually results in structure destruction. Herein, dandelion-like Mn/Ni co-doped CoO/C hollow microspheres (CMNC-10h) are synthesized via an Ostwald ripening process without templates. The high-angle annular dark field mapping images at the atomic level indicate the successful doping of Mn and Ni into CoO. Via an annular bright field image, oxygen vacancies induced by doping can be clearly observed. The residual two electrons in the oxygen vacancy site are highly delocalized, as confirmed by density functional theory calculations, effectively improving electrical conductivity. According to electron holography analysis, the dielectric polarization field in superficial regions of primary nanoparticles can facilitate insertion of Li + ions into nanoparticles and thus enhance electrochemical kinetics. Combining those advantages, CMNC-10h demonstrates a high capacity of 1126 mAh g −1 at 1 A g −1 after 1000 cycles as anode material for a lithium-ion battery. Additionally, based on the strong adsorption toward polysulfide, the porous structure to accommodate sulfer/polysulfide, and the effects of oxygen vacancies to immobilize and catalyze polysulfide, CMNC-10h-S as cathode material for a lithium−sulfur battery also displays a high capacity of 642 mAh g −1 after 500 cycles at 1 C.

Copper vanadate nanobelts were synthesized by a facile hydrothermal process and used for the electrochemical determination of ascorbic acid.

Achieving strong adsorption and catalytic ability toward polar lithium polysulfide species (LiPSs) of the sulfur host in lithium–sulfur (Li–S) batteries is essential for their electrochemical cyclic stability. Herein, a strategy of “self‐termination of ion exchange” is put forward to synthesize the novel yolk‐shell sulfur host composed of ZnO nanoparticles confined in Co‐doped NiO (CDN) polyhedron (ZCCDN). After sulfur infiltration, the obtained S/ZCCDN cathode achieves excellent performance of 738.56 mAh g−1 after 500 cycles at 0.5 C with a very low capacity decay rate of only 0.048% per cycle. Even at 1 C, 501.05 mAh g−1 could be retained after 500 cycles, suggesting a capacity decay ratio of only 0.076% per cycle. The good cycle performance is attributed to the improved LiPSs’ conversion kinetics, which originates from ZCCDN's sturdy chemical affinity and strong catalytic ability to polar LiPSs. For the first time, by electron holography, the local interfacial polarization electric field is clarified to be existed in the material which is conducive to the capture of LiPSs and the migration of electrons and Li+ from the mesopores. This work provides a rational way for the use of zeolitic imidazolate frameworks (ZIFs) and development of cathode materials for Li–S batteries.